This invention is in the field of positioning and detecting means and is more specifically directed to a scanner which is positionable on a casting or other item for locating internal flaws by means of a conventional transducer mounted on the scanner.
Prior devices have been proposed for the purpose of scanning items such as castings with such devices usually employing hand-held transducers or possibly motor driven scanner supports which progressively traverse the entire surface of a survey area of the item being inspected. Such scanners are costly and time consuming in use. There has consequently been an unmet need for a simple and portable scanner which can be manually operated for detecting the location of internal flaws in metal and other bodies repeatably. The provision of such a scanner is the primary object of this invention.
Achievement of the object of this invention is enabled through the preferred embodiment which comprises a portable frame on which a carriage is mounted for reciprocation. Reciprocation of the carriage effects rotation of a threaded rod engaged by a drive pin on the carriage with the rod driving a first rotary encoder providing an output in accordance with the extent and direction of rotation of the rod. The carriage supports a slide carrier means for reciprocation perpendicular to the direction of movement of the carriage on the frame with a transducer being mounted on the slide carriage means so that it is positioned immediately adjacent a body over which it is to be moved for scanning purposes. A second threaded rod is rotated by movement of the slide carrier means to rotate a second rotary encoder. Both encoders are connected to display members which provide a visual indication of the count in each encoder and consequently provide a visual indication of the position of the transducer along perpendicular axes at any particular moment, such as when the transducer detects a flaw in the body being scanned. It is consequently possible for the operator to immediately pinpoint the location of the flaw by noting the coordinate position of the transducer as indicated by the display members.